Mesh HWMP module will be able to rely on the HW
RC algorithm if it exists, for path metric calculations.
This allows the metric calculation mechanism to calculate
a correct metric, based on PER and last TX rate both via
HW RC algorithm if it exists or via parameters collected
by the SW.
Signed-off-by: Maxim Altshul <[email protected]>
---
Changed the function to return u32, I agree that this
is much clearer.
As for the rate, two things:
1. I had to divide the returned value by 100, since
drv_get_expected_throughput returns values in units of Kbps.
On the contrary, the function cfg80211_calculate_bitrate
returns in units of 100Kbps, so a correction is needed.
2. Why return the value into rate?
As I understand, rate here is actually bitrate,
and so, we have two possible outcomes:
- A SW/HW RC algo does exist, and an estimated throughput is
returned. err is set to 0 (as it is already included in the RC algo)
and the airtime is calculated using the estimated throughput.
- A SW/HW RC algo does not exist, and thus the regular calculation
takes place, in which an estimated throughput is calculated
using the bitrate and the err parameter.
>From this calculation the airtime is calculated.
net/mac80211/mesh_hwmp.c | 25 +++++++++++++++++--------
net/mac80211/sta_info.c | 23 +++++++++++++++++++----
net/mac80211/sta_info.h | 2 ++
3 files changed, 38 insertions(+), 12 deletions(-)
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index c6be0b4..ad67f46 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -322,19 +322,28 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
int device_constant = 1 << ARITH_SHIFT;
int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
int s_unit = 1 << ARITH_SHIFT;
- int rate, err;
+ int rate = 0, err = 0;
u32 tx_time, estimated_retx;
u64 result;
- if (sta->mesh->fail_avg >= 100)
- return MAX_METRIC;
+ /* Try to get rate based on HW/SW RC algorithm.
+ * Rate is returned in units of Kbps, correct this
+ * to comply with airtime calculation units
+ */
+ rate = sta_get_expected_throughput(sta) / 100;
+
+ /* if we did not get a rate */
+ if (!rate) {
+ if (sta->mesh->fail_avg >= 100)
+ return MAX_METRIC;
- sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
- rate = cfg80211_calculate_bitrate(&rinfo);
- if (WARN_ON(!rate))
- return MAX_METRIC;
+ sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
+ rate = cfg80211_calculate_bitrate(&rinfo);
+ if (WARN_ON(!rate))
+ return MAX_METRIC;
- err = (sta->mesh->fail_avg << ARITH_SHIFT) / 100;
+ err = (sta->mesh->fail_avg << ARITH_SHIFT) / 100;
+ }
/* bitrate is in units of 100 Kbps, while we need rate in units of
* 1Mbps. This will be corrected on tx_time computation.
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 63ea6cb..fa2c507 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2069,14 +2069,29 @@ void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
if (test_sta_flag(sta, WLAN_STA_TDLS_PEER))
sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_TDLS_PEER);
+ thr = sta_get_expected_throughput(sta);
+
+ if (thr != 0) {
+ sinfo->filled |= BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT);
+ sinfo->expected_throughput = thr;
+ }
+}
+
+u32 sta_get_expected_throughput(struct sta_info *sta)
+{
+ struct ieee80211_sub_if_data *sdata = sta->sdata;
+ struct ieee80211_local *local = sdata->local;
+ struct rate_control_ref *ref = NULL;
+ u32 thr = 0;
+
+ if (test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
+ ref = local->rate_ctrl;
+
/* check if the driver has a SW RC implementation */
if (ref && ref->ops->get_expected_throughput)
thr = ref->ops->get_expected_throughput(sta->rate_ctrl_priv);
else
thr = drv_get_expected_throughput(local, &sta->sta);
- if (thr != 0) {
- sinfo->filled |= BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT);
- sinfo->expected_throughput = thr;
- }
+ return thr;
}
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 2cafb21..5c9c8be 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -661,6 +661,8 @@ void sta_set_rate_info_tx(struct sta_info *sta,
struct rate_info *rinfo);
void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo);
+u32 sta_get_expected_throughput(struct sta_info *sta);
+
void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
unsigned long exp_time);
u8 sta_info_tx_streams(struct sta_info *sta);
--
2.9.0
On Thu, 2016-06-30 at 18:30 +0300, Maxim Altshul wrote:
> Mesh HWMP module will be able to rely on the HW
> RC algorithm if it exists, for path metric calculations.
>
> This allows the metric calculation mechanism to calculate
> a correct metric, based on PER and last TX rate both via
> HW RC algorithm if it exists or via parameters collected
> by the SW.
>
> Signed-off-by: Maxim Altshul <[email protected]>
> ---
> Changed the function to return u32, I agree that this
> is much clearer.
> As for the rate, two things:
> 1. I had to divide the returned value by 100, since
> drv_get_expected_throughput returns values in units of Kbps.
> On the contrary, the function cfg80211_calculate_bitrate
> returns in units of 100Kbps, so a correction is needed.
> 2. Why return the value into rate?
> As I understand, rate here is actually bitrate,
> and so, we have two possible outcomes:
> - A SW/HW RC algo does exist, and an estimated throughput is
> returned. err is set to 0 (as it is already included in the RC algo)
> and the airtime is calculated using the estimated throughput.
> - A SW/HW RC algo does not exist, and thus the regular calculation
> takes place, in which an estimated throughput is calculated
> using the bitrate and the err parameter.
> From this calculation the airtime is calculated.
>
> net/mac80211/mesh_hwmp.c | 25 +++++++++++++++++--------
> net/mac80211/sta_info.c | 23 +++++++++++++++++++----
> net/mac80211/sta_info.h | 2 ++
> 3 files changed, 38 insertions(+), 12 deletions(-)
>
> diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
> index c6be0b4..ad67f46 100644
> --- a/net/mac80211/mesh_hwmp.c
> +++ b/net/mac80211/mesh_hwmp.c
> @@ -322,19 +322,28 @@ static u32 airtime_link_metric_get(struct
> ieee80211_local *local,
> int device_constant = 1 << ARITH_SHIFT;
> int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
> int s_unit = 1 << ARITH_SHIFT;
> - int rate, err;
> + int rate = 0, err = 0;
The rate init is wrong - you overwrite it immediately.
The err init is questionable - I think it might be better to write
if (rate) {
err = 0;
} else {
...
}
below?
> u32 tx_time, estimated_retx;
> u64 result;
>
> - if (sta->mesh->fail_avg >= 100)
> - return MAX_METRIC;
> + /* Try to get rate based on HW/SW RC algorithm.
> + * Rate is returned in units of Kbps, correct this
> + * to comply with airtime calculation units
> + */
> + rate = sta_get_expected_throughput(sta) / 100;
> +
> + /* if we did not get a rate */
> + if (!rate) {
Maybe you want DIV_ROUND_UP to account for getting a very lot estimated
rate (< 100Kbps) returned, which isn't "no rate"?
Ohterwise looks fine.
johannes